Mobile phone users have fewer brain tumours

Analysis Mobile users have a lower risk of developing brain cancers than non-mobile users, a ten-year €19m study by the UN has shown. But the epidemiologists are doubtful about the results, which aren't alarmist enough, and have called for more funding additional research.

The study by the Interphone International Study Group, which began in 2000, was supervised by the UN's WHO arm and conducted in 13 countries. Researchers examined the occurrence of four kinds of tumours: two brain tumours (glioma and meningioma), tumours of the acoustic nerve (schwannoma) and cancer of the parotid gland. Regular mobile phone users saw a lower chance of developing brain tumours, with relative risk ratios (ORs) of 0.81 for glioma and 0.79 for meningioma.

"ORs were < 1.0 for all deciles of lifetime number of phone calls and nine deciles of cumulative call time," says the WHO in a summary. The highest the team could find occured in just one decile, where the hazard ratio for developing glioma tumours was 1.40. This is statistically insignificant: a relative risk ratio of less than two is not considered worthy of attention, the National Cancer Institute said in 1994, and an RR of 3.0 or higher is usually necessary.

Successive studies have shown no association between mobile use and cancer, an outlier being a Swedish researcher who found no link for most groups, but RRs of 5.2 for under 20s - only with a very small sample.

End of story, then?

You must be joking.

The group rubbishes its own work saying that lower odds may reflect "participation bias or other methodological limitations", which you think they might have worked on over ten years. "Biases and errors limit the strength of the conclusions that can be drawn from these analyses", they insist.

Meanwhile Christopher Wild, director of the UN's cancer quango the International Agency for Research on Cancer, made what sounds like a bid for permanent employment.

"An increased risk of brain cancer is not established from the data from Interphone," he admitted. "However, observations at the highest level of cumulative call time and the changing patterns of mobile phone use since the period studied by Interphone, particularly in young people, mean that further investigation of mobile phone use and brain cancer risk is merited."

Of course. They need to torture the numbers until they confess.

The WHO acknowledges that newer and better technology means lower RF emissions, as does "the increasing use of texting and hands-free operations that keep the phone away from the head".

The EU-funded MobiKids survey will report in a year's time on phone usage amongst young people. More at the WHO on EMF over here. ®